The present invention relates to a molten iron containing vessel with an improved inner refractory lining. The present invention is particularly directed to such an improved vessel of the type employed for transporting and desulfurizing pig iron.
More specifically, this type of vessel or container may include a pipe or tubular area or portion, an end area or portion facing the tubular portion, and a gate or runner area or portion through which iron may be charged into the interior of the vessel. A refractory fireproof inner lining is provided on the interior of such vessel. In this type of vessel, the inner refractory lining may include dolomite bricks, particularly tar bonded dolomite bricks, in the tubular and end areas of the lining.
Chamotte bricks, high alumina content bricks such as bauxite, mullite and corundum bricks, as well as more basic bricks such as dolomite, magnesia and magnesia-chrome bricks are used for the inner lining of this type of container, which conventionally is operated at temperatures of approximately 1400.degree. to 1600.degree. C. For desulfurization of pig iron inside such a vessel, tar bonded, tempered dolomite bricks are recommended. For other situations however, bauxite bricks are recommended (C. Muller: Present Developments in the Lining for Transfer Ladles, "Sprechsaal 1976," a discussion corner in a magazine, pp. 156 to 161, and H. Hofges et al.: Operational Experience with Transfer Ladles with Linings made of Chamotte, High Alumina Cement, Magensite and Dolomite, XVIII International Fireproof Colloquy in Aachen, October 1975; a collection of lectures, pp. 84 to 100).
When the refractory lining is constructed of relatively inexpensive dolomite bricks, slag which develops during the desulfurization process is easily deposited on the lining, particularly in the lower part of the end portion of the vessel. This leads to a reduction of the interior volume of the vessel. Unlike dolomite bricks, bauxite bricks have a much higher durability and resistance to erosion, and therefore are of interest for the charging or gate portion of the lining. Thus, it has become the practice to employ a combination of the two types of bricks, i.e. bauxite bricks in the gate portion of the lining, and dolomite bricks in the tubular and end portions of the lining. Such a lining construction however causes a weakening of the brickwork in the areas where the two types of bricks join, due to contact reactions between the two types of materials. Also, there results an undesirably heavy formation of slag in the end portion or area of the vessel.